A guide to acronyms (and abbreviations), words and phrases used throughout the Environment Canterbury website. Look in the 'By Subject' tab to find groups of terms relevant to a specific topic.

Some terms might have definitions in addition to those in this glossary.

Use the online Māori Dictionary to help with translating words between Te Reo Māori/English.

Abatement notice
a formal written notice that the Resource Management Act 1991 (RMA) specifies can be issued only by a warranted enforcement officer, requiring certain actions to be taken or to cease within a specified time where that enforcement officer believes on reasonable grounds (on the balance of probabilities) that there is or is likely to be a contravention of the RMA or an adverse effect on the environment.
in relation to a water body, means the taking of water from that water body.
Affected parties
people who may experience an effect as a result of a proposal which is significantly greater than or different from the effect on the general public.
Air Plan
the Proposed Canterbury Air Regional Plan sets out how we are going to manage air pollution from home heating, industry and other sources like outdoor burning, dust and odour.
in relation to air quality, means background air quality. Ambient conditions are those not modified by specific sources.
Amenity values
natural or physical qualities and characteristics of an area that contribute to people's appreciation of its pleasantness, aesthetic coherence, and cultural and recreational attributes.
Annual Exceedance Probability
the probability of a certain size of flood flow occurring in a single year.
Annual Volume
is the total amount of water authorised via a water permit over a one-year period.
Annual Volume calculator
is an Excel spreadsheet which is intended to enable calculation of an annual volume for a specific area of irrigated land.
Appurtenant structure
in relation to a dam, means a structure that is integral to the safe functioning of the dam as a structure for retaining water or other fluid.
an underground gravel channel through which groundwater flows.
edible fern root.
Assessment of Environmental Effects
a report provided with a resource consent application. It outlines the effects that the proposed activity might have on the environment.
Agricultural and Pastoral
Accident Compensation Corporation
Assessment of Environmental Effects
Alternative Environmental Justice
Annual Exceedence Probability
Amuri Irrigation Collective
Automatic Identification System
ante meridiem = morning (before noon)
ad medium filium
Average Recurrence Interval
above sea level

Annual Volume

Annual volume
is the total amount of water authorised via a water permit over a one year period. For irrigation permits, this is determined as being the volume required during an irrigation season, calculated according to Schedule WQN9 version 3.
Annual volume calculator
is an Excel spreadsheet which is intended to enable calculation of an annual volume (water authorised via a water permit over a one year period) for a specific area of irrigated land.
Go to the Annual Volume calculator.
Aquifer (annual volume definition)
saturated, permeable geological unit that is capable of yielding economically significant quantities of water to wells or springs.
Effective irrigation season rainfall
is the amount of rain that will contribute to crop growth over the nominal irrigation season. In determining this amount, provision has been made for:
  • rainfall that occurs in 4 out of 5 years, and
  • excluding daily rainfall amounts of less than 5 mm, or cumulative rainfall amounts in consecutive days in excess of 50 mm.
Instream values
non-consumptive values associated with a water-body—includes aquatic ecosystem values, natural character and landscape values, Ngāi Tahu values and amenity and recreational values.
Profile Available Water (PAW)
reflects the soil's capacity to hold water assessed for the soil profile to a depth of 0.9 metres and expressed as millimetres of water.
Schedule WQN9
sets out the way in which a seasonal irrigation demand standard is to be determined.
Seasonal Irrigation Demand Standard
is, for a given land use, soil PAW and effective irrigation season rainfall, the depth of water (measured in millimetres) per hectare per year required to be supplied by irrigation to satisfy plant water demand after allowing for effective irrigation season rainfall. The seasonal irrigation demand standard has 2 roles in the Natural Resources Regional Plan:
  • water use for irrigation which complies with the standard is treated as a permitted activity, and
  • the standard is used to determine effective groundwater allocation in circumstances where annual volumes are not specified as part of the water permit.
Soil Moisture-Effective Rainfall
is a single layer within GIS that combines the soil PAW layer and the effective irrigation season rainfall layer.
System capacity factor
is based on the reduced ability to meet irrigation demand when the consented system capacity is below a specified threshold. Where the consented system capacity is greater or equal to 4.0 mm/day, the system capacity factor is assigned a value of 1.0, on the basis that the total seasonal demand can be met at all times, and therefore 100% of the volume calculated using Schedule WQN9 version 3 can be delivered. Where the consented system capacity is below 4.0 mm/day, then the ability to meet the total seasonal demand will be constrained. Environment Canterbury has developed an in-house method to determine the system capacity factor using 34 years of daily rainfall and potential evapotranspiration data to calculate the ratio between unconstrained and constrained demand. Due to constraints regarding both the size and the distribution of this data, it is not possible for us to make this available on-line. However, the data can be requested from the National Institute of Water and Atmospheric Research Ltd (NIWA). If you require a system capacity factor, you can either: contact Environment Canterbury and request this be completed; or contact a groundwater consultant who may be able to obtain the climate data.
Total seasonal demand
is the total amount of water required to satisfy plant water needs during the main growing period. This demand can be satisfied by rainfall and irrigation. In determining the irrigation component, provision has been made for:
  • an application efficiency of 80%
  • a system capacity to meet peak demand between 4.0 and 6.5 mm/day
  • a nominal irrigation season from 1 October to 30 April, and
  • demand conditions that occur in 4 out of 5 years.